LED lighting engines have become ever popular in recent years. It not only offers a longer life span, but also operates with lower power consumption that results in energy saving and thus is more environmental-friendly. LED can find applications in many areas including, for example, general lighting, decorative lighting both indoors and outdoors, security systems, and replacement of existing light sources such as the fluorescent lamps and halogen lamps.
More and more researches have been done to increase LED brightness at the same power level (Im/W), and many driving schemes have been proposed. However, relatively less attention has been paid to safety aspect of the LED applications. Practically, other than the existing generally applicable safety approval tests, which necessarily require sophisticated integrated controller and/or sensing modules or components, there is no safety tests or measures designed specifically for LED appliances which are simple and yet provide guarantee that the LED product would not injure users under any conditions, especially when the LED product is intended to replace the ones used in existing infrastructures. A good example can be found where LED tubes (array) are used to replacing fluorescent tubes. There is a need for developing a new current leakage protection device specific for LED applications.